Magnetic pulse compression circuits adapted for generating a pulse having a high output and a short pulse duration have been used in pulse power source apparatuses used in lasers and particle accelerators. The magnetic pulse compression circuits compress a current pulse duration utilizing a saturation characteristic of a saturable magnetic core when the charge of a capacitor is shifted to a capacitor of a next stage.
An induction magnetic core of a linear accelerator essentially operates as a 1:1 transformer and accelerates a charged particle beam which passes through the central portion of the magnetic core by means of a voltage generated in a secondary gap.
Heretofore, as these magnetic cores for high output pulse there have been used magnetic cores wherein magnetic material ribbons such as iron-base amorphous alloy ribbons or cobalt-base amorphous alloy ribbons having characteristics such as high saturation magnetic flux density, a high squareness ratio of a magnetization curve and a low core loss and electrical insulating materials composed of a polymeric film such as a polyester film or polyimide film are alternately wound.
In such magnetic cores, an insulating property between magnetic material ribbons is important because the magnetic cores are used in high output pulse applications. Therefore in the prior art in order to ensure layer insulation between magnetic material ribbon edges, the electrical insulating materials and the magnetic material ribbons have been set so that the width of the electrical insulating materials is wider than the width of the magnetic material ribbons.
However, we have now found that the following problems pose in the magnetic cores wherein the width of the electrical insulating materials is wider than the width of the magnetic material ribbons in order to ensure layer insulation between magnetic material ribbons as described above.
That is, as shown in FIG. 2 which is a schematic view of a cross-section of the prior art magnetic core, the edges of an electrical insulating material 2 projects from the edges of a magnetic material ribbon 1. Further, in general the electrical insulating material 2 has a low heat conduction property and therefore the space between the projected portions of the electrical insulating material 2 can be a thermal insulation layer 3. Accordingly, an effect of cooling on the heat generation of magnetic cores in use, in other words, the heat generation of magnetic material ribbons is reduced and thus the temperature of the magnetic cores can rise. In general, while the magnetic cores are cooled by coolant such as air, insulating oils, and fluorine-containing inert liquids, the temperature rise of the magnetic cores can result in the reduction of the magnetic flux of the magnetic cores and the acceleration of secular change of characteristics and there is inevitably occurred a problem that specific functions are not obtained.
An object of the present invention is to solve the problems described above and provide a magnetic core having an excellent cooling characteristic.